It's an inside joke if you've ever watched Shofu's Let's Play videos of Pokemon Reborn. Someone criticized him for not catching Pidove, because it "evolves into a powerful Staraptor". So the commenters went wild with making jokes of Bidoof evolves into a powerful Staraptor, Kirlia is garbage, but it'll evolve into a powerful Staraptor. Stuff like that. xD

Firestone can be found in one of the lowest room's rock in Pyrous Mountain. I heard where Heatmor is. I've never seen it there personally. xD It can also be found through mining, but that took me 1000 tries. xD